The subject matter disclosed herein relates to the art of turbomachines and, more particularly to a dovetail seal for a turbomachine rotor blade.
Turbomachines typically include a compressor portion, a turbine portion, and a combustor assembly. Air passes through a number of compressor stages in the compressor portion and is compressed to form compressed air. A portion of the compressed air is passed to the combustor assembly, mixed with a combustible fluid, and combusted to form gases that are passed to the turbine portion. The gases expand through a number of turbine stages to create work. Each of the compressor stages and turbine stages include a rotor wheel to which is mounted a plurality of blades or buckets. The buckets react to the airflow or gases and impart a rotational force to the rotor wheel.
The buckets are typically mounted to the rotor wheel through a dovetail attachment. Generally, the blade will include a pin and the rotor wheel will include one or more slots that are sized to receive the pin. In some cases, pluralities of slots extend laterally across an outer diameter surface of the rotor wheel. In such cases, the rotor wheel will include a slot for each blade. In other cases, a single slot extends circumferentially about the outer diameter surface of the rotor wheel. In such cases, the slot is off-set from a centerline of the outer diameter surface and will include a loading portion. The loading portion is configured to receive each blade. Each blade is mounted to the rotor wheel and manipulated into place about the outer diameter surface. Once all blades are mounted, locking features are secured to the rotor wheel near the loading portion to prevent blade liberation. When using a plurality of slots, each pin will include a seal that is configured to engage with internal surfaces of the slot to reduce fluid leakage across the rotor wheel.